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See also Power Optimizers for generalities about these devices.

The SolarEdge distributed architecture is based on a unique system design approach, characterized by a distributed DC-DC power optimizer for each PV module (or group of PV modules). These optimizers, with a current-driven output, are connected in series as strings, which are then connected in parallel to the input of a special (proprietary) inverter.

Each power optimizer can manage 1 to 4 PV modules, and performs the MPP tracking at the input module (or group of modules) level.

The SolarEdge optimizers work in Buck-Boost mode.

The specificity of the SolarEdge inverters is that the voltage of the full optimizers string is fixed  (usually 350V or 700V for most inverters), so that the current of the whole string  (i.e. each optimizer output) is imposed according to the available PV power at Pmpp of each input module.

During the simulation, the efficiency of each optimizer is evaluated. It depends on the Current boost ratio (the longer optimizer string, the lower efficiency).    

Operating at a fixed voltage means that the Power Optimizers in a string operate completely independently one from the other, so that at a given time the module productions may be different without any effect on the system (shadings, mismatch, different orientations, etc).

In PVsyst this requires a very special procedure for the elaboration and sizing of the system.

 

Parameter

The main relevant parameters of a SolarEdge Power Optimizers are:

The main parameters used for the sizing of the inverter are:

Sizing

The sizing rules for SolarEdge devices are extremely complex:

- only specific optimizers are compatible with specific inverters.

- the minimum and maximum number of optimizers in a string is defined for each association  Optimizer-Inverter.

- the maximum number is also limited by a maximum admissible power for one string.

- each inverter may be undersized by a Pnom Ratio specified for each model  (usually 1.35, some models with 1.55).

These complex rules lead to define the SolarEdge systems with a very new concept in PVsyst, i.e. create a list of "physical" inverters, and associate different strings to each of them.  See the "SolarEdge Procedure"  page for further details.

Power Optimizer parameters definition

The available Power Optimizers and their parameters may be displayed in the SolarEdge optimizer definition (specialized optimizer parameters dialog). As the Power Optimizer are proprietary devices of SolarEdge, their parameters are not directly modifiable, but only defined in the original database of PVsyst.

System sizing

As with any usual system, you are advised to start by specifying the required power for your subfield (or the available area). After that you have to choose a PV module.

When choosing a SolarEdge optimizer, the system sizing dialog will change to a suited dialog for the SolarEdge architecture, and predefine the number of required optimizers for your system size.

You have first to choose the Power Optimizer to be used in your system (in the PV module group).

Then in the Array design part, please define the Power Optimizer input configuration, i.e. the number of PV modules connected to each Power Optimizer (according to number of available inputs).  

Then you define the inverter input:

This very important information indicates how many identical strings you can connect on one inverter. For example if more that 50%, only one string of that length can be connected to each inverter.

You are of course advised to use the  "Show Sizing" tool for visually checking the sizing of this sub-field.

Systems with different strings

When you have strings with different lengths, you should define different sub-arrays, one for each length to be defined.

In each sub-array, you have to define a number of strings, and a number of concerned inverters. This means the number of physical inverters which will receive one or more of the strings defined in this sub-array.

The attribution of different strings to different physical inverters is done in a specific dialog to be open with the button "Strings configuration". This dialog is described in the previous page SolarEdge Procedure.

Simulation

With distributed SolarEdge architecture: